Re: The 🐑 Shepherd gets a service collection

[Ludovic Courtès]

Hi,

Adam Faiz <adam.faiz@disroot.org> skribis:

>> I imagine we could develop more convenient services like this, such
>> as basic command scheduler similar to the ‘at’ command, and a
>> syslogd
>> implementation.  The latter could be nice for a couple of reasons:
>> logging would happen from the start and till the end (an improvement
>> over the external syslogd process), and it could let us provide a nicer
>> user interface to view logs (taking inspiration from that of
>> ‘journalctl’).
>> Thoughts?  Ideas?I don't think a command scheduler should be added
>> to the Shepherd, isn't that what mcron does?
> If mcron has any deficiencies for being used as an `at` command, then that 
> can be improved.

The main limitation of mcron for such thing is that it’s entirely
static: it reads a list of job specs upfront and then goes on to
schedule them.  There’s no communication protocol to talk to it and
add/remove jobs on the fly, which is what ‘at’ would need.

> Regarding syslogd, I think a better approach is to tell the services to send 
> their output to stdout and stderror,
> so that logs don't depend on a separate logging service in the first place.

Yes, but:

  1. Some daemons include syslog support even today, sometimes optional,
     sometimes mandatory.

  2. Syslog is a bit more structured than just stdout/stderr output:
     there are facilities and levels, for instance—see syslog(3);
     syslogd provides interesting filtering capabilities.

> Per-service logging is already implemented in the Shepherd, but could be 
> streamlined to have a default logs directory:
> https://skarnet.org/software/s6/s6-log.html#loggingchain

Interesting read, thanks!

Regarding the default logs directory, there’s /var/log already, or did
you mean something else?

Thanks,
Ludo’.